Current Driven Floating Driver Circuit

1. A circuit for generating a modulated signal, comprising: a constant current source; a first switch coupled to the constant current source; a second switch coupled to the first switch and a ground, wherein the first switch and the second switch are coupled to a third switch, the third switch is coupled to a first integrated circuit pad, wherein the first integrated circuit pad is defined to be used for coupling the third switch to a resonance circuit and a fourth switch coupled to the ground and a fifth switch.

2. The circuit of claim 1 , wherein the fifth switch is coupled to a second integrated circuit pad, wherein the second integrated circuit pad is defined to be used for coupling the fifth switch to the resonance circuit.

3. The circuit of claim 1 wherein the circuit is embodied in one single integrated circuit having the first integrated circuit pad and the second integrated circuit pad.

4. The circuit of claim 3 , wherein the one single integrated circuit is configured to be connected to the resonance circuit that includes a coil and a capacitor, wherein the coil and the capacitor are connected in parallel.

5. The circuit of claim 1 , wherein the first switch, the second switch and the third switch are configured to be operated by a plurality of signal sources, each of the plurality of signal source is configured to produce different types of digital control signals.

6. The circuit of claim 5 , wherein the digital control signals are arranged to produce Amplitude Shift Keying (ASK) modulation.

7. The circuit of claim 5 , wherein the digital control signals are arranged to produce Phase Shift Keying (PSK) modulation.

8. The circuit of claim 1 , wherein the second switch is fast off switch having a second gate to increase turn off speed of the second switch.

9. There circuit of claim 1 , wherein the third switch is a NMOS transistor.

10. A circuit for generating a modulated signal, comprising: a first constant current source; a first switch coupled to the constant current source; a second switch coupled to the first switch and a ground, wherein the first switch and the second switch are coupled to a third switch, the third switch is coupled to a first integrated circuit pad; and a second current source coupled to a fourth switch that is coupled to a fifth switch, wherein the fifth switch is coupled to a sixth switch, the sixth switch is coupled to a second integrated circuit pad.

11. The circuit of claim 10 , wherein the first current source and the second current source are outputs of a same current source.

12. The circuit of claim 10 , wherein the first current source and the second current source are independent circuits coupled to a same power source.

13. The circuit of claim 10 , wherein the third switch and the sixth switch are NMOS transistors.

14. A circuit for generating a modulated signal, comprising: a first constant current source coupled to a first switch; a second constant current source coupled to a second switch and a ground, wherein the first switch is coupled to the second switch, wherein the first switch and the second switch are coupled to a third switch; and a third constant current source coupled to a fourth switch, the fourth switch is coupled to a fifth switch, wherein the fifth switch is coupled to a fourth constant current source, wherein the fourth switch and the fifth switch are coupled to a sixth switch, wherein the first switch and the second switch are coupled to the fourth switch and the fifth switch through a seventh switch.

15. The circuit of claim 14 , wherein the third switch is coupled to an eighth switch that is coupled to a first integrated circuit pad.

16. The circuit of claim 15 , wherein the sixth switch is coupled to a ninth switch that is coupled to a second integrated circuit pad.

17. The circuit of claim 14 wherein the third switch is further coupled to a ground.

18. The circuit of claim 14 , wherein the first constant current source and the second constant current source are outputs of a same current source.

19. The circuit of claim 14 , wherein the first constant current source and the second constant current source are outputs of different current sources.